Process for producing manifolded forms

ABSTRACT

A process is described for producing a manifolded business form from a plurality of superimposed plies of printable material. Each of the plies has at least one adhesive covered portion thereto for joining the plies together. In the process, the plies are fed along a path so as to expose the adhesive covered portion to microwave energy which effects setting of the adhesive. While the adhesive is setting, squeezing pressure is applied periodically to a number of spots in each adhesive covered portion to disable any tendency of the plies to separate.

' March 13, 1973 H. F; BORROW I 3,720,561

PROCESS FOR PRODUCING MANIFOLDED FORMS Filed Jan. 20, 1970 2 SheetsSheet t.

13, 1973 H. E. BORROW 39726361 PROCESS FOR PRODUCING MANIFOLDED FORMS Filed Jan. 20, 1970 2 Sheets-Sheet a2 '13 3 2O\ \M Z E O. 2\ Em I h "-34 2 32 A r 25' 38 36 72 26 A F h I .1 A: 3-

FIG. 2

United States Patent 3,720,561 PROCESS FOR PRODUCING MANIFOLDED FORMS Henry E. Darrow, Ottawa, Ontario, Canada, assignor to R. L. Crain Limited, Ottawa, Ontario, Canada Filed Jan. 20, 1970, Ser. No. 4,269 Int. Cl. B32b 31/20 US. Cl. 156-272 6 Claims ABSTRACT OF THE DISCLOSURE A process is described for producing a manifolded business form from a plurality of superimposed plies of printable material. Each of the plies has at least one adhesive covered portion thereto for joining the plies together. In the process, the plies are fed along a path so as to expose the adhesive covered portion to microwave energy which effects setting of the adhesive. While the adhesive is setting, squeezing pressure is applied periodically to a number of spots in each adhesive covered portion to disable any tendency of the plies to separate.

This invention relates to a novel method for providing a closer bonding together of a plurality of superimposed plies of paper or other such printable material. More particularly, the present invention relates to a new method which is carried out in connection with a rigid wave guide wherein microwave energy is used for setting glue, or other adhesive on portions of the superimposed plies that may be in sheet, strip or web form and which make up a manifolded business form.

It is known in the art of business forms to effect the drying and setting of glue, for example, or other adhesive per se by means of microwave energy. Such energy is controlled and tuned within a Wave guide made either entirely of an electrically conductive metal, or at least coated on the interior thereof with such a metal, and this energy is passed through the glue to generate heat internally therein causing evaporation of the moisture contained in the glue to dry the same. It has been a problem, however, to ensure a good close bonding of the superimposed plies of paper or other sheet material, simultaneously with the drying of the glue which bonds such plies together. In this respect, a problem that is frequently encountered involves the tendency for the superimposed sheets, strips or webs to spread or float apart while the glue or adhesive is drying and setting, such that the sheets or webs end up being poorly bonded and possibly even separated.

It is an object of this invention, therefore, to provide an improved method for promoting closer bonding together of superimposed sheets or webs simultaneously with the setting of the adhesive being used in the sheets or webs.

It is another and more particular object of this invention to produce an improved manifold business form by a method that involves setting the adhesive in the form in a rigid wave guide, and while the adhesive is setting, applying pressure periodically to the adhesive covered portion effecting closer bonding together of the superimposed plies or sheets of paper or the like printable material.

Accordingly, one form of the present invention may be embodied in a process for producing a manifolded business form from a plurality of superimposed plies of printable material, said plies each having at least one adhesive covered portion thereon to effect bonding said plies together, the improvement comprising feeding the adhesive covered portion along a predetermined path to expose the same to microwave energy for effecting setting of said adhesive; and while the adhesive is setting, periodically applying squeezing pressure to a number of spots in each adhesive covered portion to ensure that said plies are joined together with minimum of separation thereof.

In yet another and more preferred form of the present ICC invention, there is provided a process for producing a manifolded business form from a plurality of superimposed plies of a printable material, said plies each having been previously printed with indicia and adhesive covered portions, comprising feeding said plies along a predetermined path to expose the adhesive covered portions to microwave energy to effect setting of the adhesive; and while the adhesive is setting, periodically applying a squeezing pressure to selected spots of the adhesive covered portions from opposite sides of the superimposed plies to maintain said plies in close relation one to another until the adhesive has set.

Such a method will now be described in more detail with reference to the accompanying illustrative drawings, in which:

FIG. 1 is a plan view, partly broken away and showing the forward portion of one form of apparatus that operates in accordance with the present invention,

FIG. 2 is an elevation view, partly in section and taken along line 2-2 of FIG. 1; and

FIG. 3 is a side elevation view, partly cut away and taken along line 3-3 of FIG. 1.

"Referring now to the drawings, a tubular, rigid wave guide is indicated at 10 and is made; for example, of copper metal or at least coated interiorly with such a metal in order that it be electrically conductive. As may be seen particularly in FIG. 2, the tubular wave guide 10 comprises front and rear walls 12 and 14, and top and bottom walls 16 and 18, respectively, These walls are all rigidly interconnected in order to define the wave guide 10, which, by way of example only, is shown as being generally rectangular in cross-section. The top and bottom walls 16 and 18 are provided with a series of vent openings 20 whose purpose will be descri-bed below, while the front Wall 12 is provided generally centrally thereof with a narrow space or slit 22 parallel to, and extending longitudinally along the length of the front Wall 12. A rigid metal partition 24 is integrally connected to the rear wall 14, with the partition being U-shaped in cross-section, see FIG. 2, to provide for the reception of an assembly of superimposed plies 25 of web, strip or sheet material. A gap 26 is formed interiorly of the wave guide 10 and is defined by the front wall 12 and the open edge of the U-shaped partition adjacent thereto. This may be clearly be seen in FIGS. 1 and 2.

The U-shaped partition 24 divides the interior of the Wave guide 10 into an upper and a lower chamber 27 and 28. A series of cooperating pairs of upper and lower rollers 30 and 50, respectively are disposed in a predetermined relation in these chambers, with the rollers 30 being located in the upper chamber 27. These rollers 30 and 50 are spaced equally apart both horizontally and vertically. As may be seen from FIG. 2, the upper rollers 30 are generally disc-shaped and are connected integrally to a cylindrical body portion 32 which is recessed at the end thereof opposite the roller 30. A connecting shaft 34 releaseably connects each of the rollers 30 to a related connector head 36 which is rigidly attached to one end of the drive shaft 38. The drive shaft 38 is rotatably journalled in bearings 40 and 42 in a two part gear-box 43, and has a spur gear 44 attached to the other end thereof opposite to the connector head 36. Each of the disc-shaped rollers 30 has a circumferential profile which originally was circular, but as may be seen from 'FIG. 3, has been cut away at 46' in order to form a number of hammer or pressure surfaces 48. The function of these hammer or pressure surfaces 48 will become apparent from the description below.

The set of lower rollers 50 are similar in construction to the rollers 30, except that the former rollers have a smooth, continuously circular profile. In a manner similar to that described relative to the rollers 30, each of the lower rollers 50 is connected integrally to a cylindrical body portion 52 which is recessed at one end thereof in order to receive and releasably retain a connecting shaft 54. This connecting shaft 54 joins each of the rollers 50 to respective ones of the connecting heads 56 on a plurality of drive shafts 58. Each of the drive shafts 58 is journalled in bearings 62 and 64 also in two part gear-box 43, as shown in FIG. 2, and carries a spur gear 66 which is driven from a main drive shaft 70. Each drive shaft 58 is also provided interiorly of the gear-box 43 with a sprocket wheel 72 which cooperates with a chain 74 in order that all of the sprocket wheels rotate in synchronism. It may be seen that the spur gear 66 which turns with the main drive shaft 70 meshes with and drives the spur gear 44 which is directly above it and on the drive shaft 38. Accordingly, it may be seen that rotation of the rollers 30 and 50 from the main drive shaft 70 is as follows. The lower rollers 50 are driven from the main drive shaft 70 by means of the drive shafts 58 and the chain-sprocket interconnection with the others of these drive shafts 58. That is to say, the right hand drive shaft 8 as seen in FIG. 1 is driven directly from the main drive shaft 70. Because the other drive shafts 58 are each interconnected to one another by means of the chain and sprockets 74 and 72, all of the shafts 5'8 and consequently all of the lower rollers 50 are driven in synchronism. In each case, the spur gears 66 on the lower drive shafts 58 rotate, and drive the associated upper spur gear 44 on the upper drive shafts 38 which are associated with the upper rollers 30. Accordingly, as the chain and sprocket 74 and 72 cause successive drive shafts 58 to rotate in synchronism, such motion is transmitted through the spur gears 66 and 44, through the upper drive shaft 38 and to the upper rollers 30.

As may be seen from FIG. 2, the gear-box 43 is essentially in two sections, which are pivotable about a pivot point 76 which may be seen in FIG. 1, in order to effect varying of the spacing or gap between the pressure surfaces 48 and the peripheral surface of the lower rollers 50. This gap may be adjusted from approximately .005 inch to .045 inch. The associated and very small angular mis-alignment of the upper section of the gear-box 43 relative to the lower section of the gear box is effected by means of a microscrew mechanism (not shown) and such mis-alignment is too small to affect the smooth operation or intermeshing of the various gears.

The operation of the above described apparatus may best be seen by referring to FIGS. 1 and 3. The plurality of superimposed plies 25 of web or sheet material is fed along on a conveyor 11 with at least one marginal portion thereof moving along within the wave guide 10, in the slot 22. The conveyor means 11 may be of a conventional construction known in the art, and will usually include sprocket wheels or the like which are engaged by complementary apertures in the superimposed plies to feed or deliver the latter as required. Furthermore, the conveyor means 11 will be driven in synchronism with the driving of the upper and lower rollers 30 and 50, all of which may be driven from a common power supply. The conveyor means 11 are so located relative to the wave guide 10 that the superimposed plies 25 being delivered thereon will enter into the slot 22 with the glued or adhesive portion of such plies being disposed in the gap 26 directly under and over the upper and lower rollers 30 and 50 respectively. It is conventional in bonding such superimposed plies 25 together to use glue or some similar adhesive either in strip or spot form over portions or regions 25' of the plies. In the context of the present invention, such regions or portions 25' of adhesive are delivered along by the conveyor means 11 and are disposed substantially within the gap 26, as described above. Accordingly, when the rigid wave guide 10 is energized and tuned, the microwave energy therein passes through the gap 26, through the upper and lower rollers 30 and 50, which are preferably made from tetrafluoroethylene or a similar material unaffected by the microwave energy, and through the adhesive where it generates heat internally. Such heat tends to cause evaporation of the moisture in the adhesive thereby causing it to dry. It may be seen therefore, that as the glued portion 25' of the strip or web material (the superimposed plies 25) enters the wave guide, it is exposed to microwave irradiation which generates heat within the adhesive causing it to dry. As drying takes place, the first complementary pair of a series of thirteen pairs of cooperating upper and lower rollers 30 and 50 will contact one location or spot on the glued portion and apply pressure against the same. The superimposed plies 25 of sheet or web material move along and, because the conveyor means 11 and the rollers 30 and 50 are driven in synchronism, the particular location to which pressure had previously been applied is again engaged by successive complementary pairs of the upper and lower rollers 30 and 50, which again apply pressure to that location squeezing the superimposed plies 25 from opposite sides thereof. Since the glue is drying simultaneously with the periodic application of pressure by the upper and lower rollers 30 and 50, good close bonding of the superimposed plies 25 may be obtained.

Without the application of such pressure or squeezing together of the superimposed plies, there is a natural tendency due to irregularities inherent in the sheet or web material which makes up the superimposed plies, tending to cause the plies to spread or float apart. It will readily be understood then, that if the glue or adhesive dries while the sheets or webs are in fact separated, poor bonding and an unattractively appearance will result. The present invention tends at least to minimize this problem.

The generation and tuning of microwave energy within the rigid wave guide 10 is believed to be known per se in the art, and it is believed unnecessary to describe such operations at this time. Furthermore, it is to be noted that although the present drawings illustrate the upper rollers 30 as being the ones which have a hammer or pressure surface thereon, these rollers 30 could in fact be interchanged with the peripherally smooth rollers 50. In yet a further variation according to the present invention, both the upper and lower rollers 30 and 50 respectively could be of a smooth continuous profile, but would be associated with a camming mechanism which periodically displaces or spreads the rollers apart such that, in effect, a repeated squeezing action of the glue or adhesive portion would result. This type of repeated squcezing action rather than continuous engagement is used since it can accommodate and will not be affected by irregularities in the registration, dimensions, quality or so on of the sheet, strip or web material which make up the superimposed plies. Such an arrangement is considerably superior to a systemhaving continuous engagement squeezing together the glued portions of the superimposed plies. Friction plates or fingers, for example, which continuously apply pressure to the plies and setting glue indeed are not feasible in practice, because of the natural tendency for some mismatch of the plies due to the inherent differences or irregularities noted above being found particularly in the lengths of continuous webs or strips. The continuous application of pressure aggravates the mismatch and ultimately causes misalignment and/ or misregistration of the Webs as they are being processed.

The apparatus and process previously described herein provide what, in effect, is at least something similar to a form of spot gluing with the result that the manifolded form so produced is more flexible, softer to handle and generally is more appealing both to a customer and to processing in data print-out equipment.

I claim:

1. In a process for producing a manifolded business form from a plurality of superimposed plies of printable material, said plies having at least one adhesive covered portion thereon for bonding said plies together, the improvement comprising the steps of feeding the superimposed plies along a predetermined path;

exposing the adhesive covered portion to microwave energy to develop heat therein which causes setting of the adhesive; and

while the adhesive is setting, periodically applying a brief intermittent squeezing pressure to each of a number of spots in each adhesive covered portion for joining said plies together with minimum of lateral separation as well as inhibiting any significant lengthwise misregistration thereof.

2. In the process of claim 1, wherein said intermittent squeezing pressure is applied to said superimposed plies from opposite sides thereof.

3. In the process of claim 2, wherein said squeezing pressure is generated by pressure surfaces which discontinuously engage the upper most and lowermost plies, said surfaces being disposed within an enclosure in which the microwave energy is present.

4. A process for producing a manifolded business form from a plurality of superimposed plies of a printable material, said plies having been previously printed with indicia and adhesive covered portions, comprising continuously feeding said plies along a predetermined path;

exposing the adhesive covered portions to microwave energy to develop heat therein which causes setting of the adhesive; and

while the adhesive is setting, periodically applying a brief intermittent squeezing pressure to each of a number of selected spots in the adhesive covered portions from opposite sides of the superimposed plies for maintaining said plies in close relation one to another until the adhesive has set, as well as inhibiting any significant lengthwise misregistration land misalignment of the plies.

5. The process of claim 4, wherein said brief intermittent squeezing pressure is produced by pressure surfaces which regularly and discontinnously engage the uppermost and lowermost plies thereby inhibiting any tendency of the plies to float apart while the adhesive is setting.

6. In a process for producing a manifolded business form from a plurality of superimposed plies of printable material, said plies having at least one adhesive covered portion thereon for bonding said plies together, the improvement comprising the steps of feeding the superimposed plies along a predetermined exposing the adhesive covered portion to microwave energy to develop heat therein which causes setting of the adhesive; and

while the adhesive is setting periodically applying a brief intermittent squeezing pressure to a number of spots in each adhesive covered portion, said spots each being engaged repeatedly during setting of the adhesive, for joining said plies together with a minimum of lateral separation as well as inhibiting any significant lengthwise misregistration thereof.

References Cited UNITED STATES PATENTS 3,325,331 6/ 1967 Schwanekamp et al. 1 5*6-290 3,560,694 2/ 197-1 White 2.19-10.'61 2,260,601 10/1941 Brenn 2-8 l-21 3,519,517 7/1970 Dench '156 197 0 2,898,973 8/1959 Marsh 156-29O X 2,364,616 12/ 1944 'Boeddinghaus 15 6--288 3,350,988 1 l/5l967 Schultz 156290 X 2,627,893 2/ 1953 Williams 156-5 82 3,196,065 7/1965 Liszewski et a1 15 6-29.l

FOREIGN PATENTS 733,932 5/1966 Canada 156290 CARL D. QUARFORTH, Primary Examiner E. E. LEHMANN, Assistant Examiner U.S. Cl. X.R. 

